Vibration dampener

ABSTRACT

A device for dampening vibrations in a rotating disc during a machining operation on the faces thereof employs a pair of blocks having friction surfaces pressed against the faces of the disc so as to be pressed tightly against the tool pieces by the rotating disc.

United St'ntes Patent 1 1 Mitchell [4 1 Jan. 16, 1973 541 VIBRATION DAMPENER 3,535,963 10/1970 Dietl ..s2/3s R 9. 3,377,752 4/1968 Border, Jr... 82/38 R x [75] Inventor e 2,745,445 5/1956 Kiawitterm. .s2/2 A Helghts, 2,734,255 2/]956 Tack ..s2/4 A 73 Assignee: Ammco ol Inc. North Chicago, 2,252,804 8/1941 Class ..82/4 A Ill. Primary Examiner-Harrison L. Hin'son [22] Fled: Maya 1 Atto'rney-Fidier, Patnaude & Lazo [21] Appl. No.: 139,394

r [57] ABSTRACT [52] U.S. Cl. ..82/38 A, 82/2 A, 82/4 A, A device for dampening vibrations rotating disc 82/])](] 19 during a machining operation on the faces thereof em- [51] Int. Cl. ..B23b 25/00 pl y :1 pai f l ck h ving friction urfaces pressed [58] Field of Search ..82/38, 38 A, 4 A, 2 A, DIG, 19 against the faces of the disc so as to be pressed tightly I 3 9 against thetool pieces by the rotating disc.

56 R f C't d l 1 I efmmgs I .e 5 Claims, 3 Drawing Figures UNITED STATES PATENTS 3,591,987-

PATENTEUJAH 16 1975 INVENTOR WALLACE F. MITCHELL ATTORNEYS VIBRATION DAMPENER The present invention generally relates to vibration dampeners, and it relates more particularly to a new and improved method and means for reducing vibra theassociated vehicle. .The vibration problem becomes particularly acute after several resurfacing operations since the disc is then substantially thinner and more subject to vibration.

Various different types of dampeners have been provided in the prior art. One' type is placed directly on one face of the disc whilethe other face is being machined. While this type of dampener performs satisfactorily, it cannot be used when both faces aremachined simultaneously. Another type of dampener fits over the periphery of the disc. It also performs satisfactorily but cannot be used with the relatively thin discs now in widespread use. I

' Therefore, a principal object of the present invention is to provide anew and improved device for dampening vibrations in a workpiece during a metal removal operation thereon. l g Another object of this invention is to provide a new I and improved device for dampening out vibrations in a disc during a metal removal operation.

A further object of this invention is to provide a new and improved device for dampening out vibrations dur ing machining of the opposite faces of a thin disc.

Briefly, the above and further objects may be realized in accordance with the teachings of the present invention by biasing a pair of rigidblocks against the faces of the disc so that the friction between the disc and the blocks forces the blocks firmly against the tool pieces in proximity to the cutting edges'thereof.

Further objects and advantages and a better understanding of the present invention may be had by reference to the following detailed description taken in connection with theaccompanying drawing in which:

FIG. 1 is a perspective view of a portion of a disc grindinglathe embodying the present invention;

FIG. 2 is a partially sectioned view showing the manner in'which the vibration dampening members directly engage the tool holders in one embodiment of the present invention; and FIG. 3is a view similar'to FIG. 2 ofanotherembodiment of-the invention 'wherein'the vibration dampening members directly engage tool bits carriedby the tool holders. Referring now to the drawings-and particularly'to FIG. lthereof, there is shown a portion of a lathe 10 including a main housing] 1 enclosing a drive mechanism for rotating an arbor on which a brake disc 121' is mounted. A tool ,holder assembly 14 isv suitably mounted on a cross-feed mechanisrmnot shown, and

- adjustabl-y supports apairlbf. axially adjustable tool pieces. The tool pieces comprise a pairof tool holders 15 and 16 and a pair of tool bits 17 and 18 tightly 12, a cut is made and vibrational waves are established in the disc. It has been found that flat, parallel faces cannot be so machined unless the vibrational waves in the disc are substantially inhibited or attenuated.

In accordance with the present invention such vibrational waves are substantially eliminated by means of a pair of vibration dampening members. 23 and 24 mounted in proximity to the tool pieces and spring biased against the faces 19 and 20 of the disc 12. As illustrated in FIG. 1 the disc moves downwardly against the tool pieces and, therefore, the members 23 and 24 are positioned above the tool pieces so as to be forced by the disc 12 directly against'the tool pieces thereby to suppress vibration of the tool pieces and of the disc.

Considered in greater detail, the dampening members 23 and 24 are solid blocks of a plastic which will not scratch or score the steel surface of the disc 12 and are biased against the opposite faces 19 and 20 of the disc by means of a spring. 25. The blocks may, if

' desired, be made of metal and provided with a plastic- 31 which is slidably mounted on the tool holder assembly 14 for adjustable movement in a direction perpendicular to the arbor of the lathe. The bracket 31 should be adjusted so that the blocks 23 and 24 are disposed directly above the tool bit holders l5 and 16, and a screw 32 is provided for holding the bracket 31 in the adjusted position. The spring 25 may be pivoted upwardly into the dotted line position as shown in FIG. 1 wherein the blocks 23 and 24 are out of engagement with the disc 12 while the tool holders l5 and 16 are adjusted to provide the desired cut. After the tool holders 15 and 16 have been thus adjusted, the spring 25 may be pivoted downwardly into the solid line position illustrated in FIG. 1 wherein the blocks 23 and 24 are spring biased against the faces 19 and 20 of the disc directly above the tool pieces. The blocks 23 and 24 have friction 'faces 33 and 34 so that as the disc 12 rotates thefriction between the blocks ,23'and 2 4 and of the present invention-the vibration dampening mem-.

bets-Z3 and 24 are held by spring pressure against the disc 12 and are held by the rotating disc against the tool whereby said pads are held tightly against said disc pieces in close proximity to the location where such and against said tool pieces. tool pieces engage the faces 19 and 20 of the disc. in 2. Apparatus for dampening vibration as set forth in this manner vibration of the tool pieces themselves are Claim 1 wherein minimized and vibration of the disc 12 is suppressed at 5 Said means mounting said pads permits relative its place of origin. movement between said pads and said tool pieces,

While the present invention has been described in and connection with particular embodiments thereof, it will Said P each have a friction disc engaging be-understood that those skilled in the art may make and are disposed on the Sides of said tool Pieces so many changes and modifications without departing as to be urged y said disc against Said tool P from the true spirit and scope thereof. Accordingly, the PP for dampening Vibration as set forth in appended claims are intended to cover all such changes clam) 2 wherem v and modifications as fall within the true spirit and Said means for urgmg a p means' scope of the present invention, 4. Apparatus for dampening vibrations as set forth in What is l i d i claim 3 further comprising 1. Apparatus for dampening vibration of a rotating means Pivotally mounting said p 'l mean$ disc during machining of the faces thereof by a pair of movement Parallel to h fafies f sald dlsctool pieces respectively engaging said faces, comprising Apparams for dampening Vibrations as set forth a pair of pressure pads, 2 means mounting Said pads against said faces in em said tool pieces comprise a pair of tool bits respecgagement with said tool pieces in proximity to the twely'moumed a of t'oolholdefsi and points of engagement between said tool pieces and 52nd pads are urged by sald d'rect engage Said faces, and ment with said tool bits. means urging said pads against said faces, 

1. Apparatus for dampening vibration of a rotating disc during machining of the faces thereof by a pair of tool pieces respectively engaging said faces, comprising a pair of pressure pads, means mounting said pads against said faces in engagement with said tool pieces in proximity to the points of engagement between said tool pieces and said faces, and means urging said pads against said faces, whereby said pads are held tightly against said disc and against said tool pieces.
 2. Apparatus for dampening vibration as set forth in claim 1 wherein said means mounting said pads permits relative movement between said pads and said tool pieces, and said pads each have a friction disc engaging surface and are disposed on the sides of said tool pieces so as to be urged by said disc against said tool pieces.
 3. Apparatus for dampening vibration as set forth in claim 2 wherein said means for urging is a spring means.
 4. Apparatus for dampening vibrations as set forth in claim 3 further comprising means pivotally mounting said spring means for movement parallel to the faces of said disc.
 5. Apparatus for dampening vibrations as set forth in claim 2 wherein said tool pieces comprise a pair of tool bits respectively mounted on a pair of tool holders, and said pads are urged by said disc into direct engagement with said tool bits. 